<title>打击犯罪(black)</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span><span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-mi">1001</span><span class="pl-p">][</span><span class="pl-mi">1001</span><span class="pl-p">],</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-mi">1001</span><span class="pl-p">],</span><span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-mi">1001</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-nf">find</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span><span class="pl-p">)</span><span class="pl-c1">//并查集</span>
<span class="pl-p">{</span>
    <span class="pl-k">return</span> <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span><span class="pl-o">==</span><span class="pl-n">x</span><span class="pl-o">?</span><span class="pl-nl">x</span><span class="pl-p">:</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">find</span><span class="pl-p">(</span><span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]);</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span>
<span class="pl-p">{</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">);</span><span class="pl-c1">//读入</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
    <span class="pl-p">{</span>
        <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">i</span><span class="pl-p">;</span><span class="pl-c1">//初始化</span>
        <span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-c1">//初始化</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">]);</span><span class="pl-c1">//读入</span>
        <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">j</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">j</span><span class="pl-o">&lt;=</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">];</span><span class="pl-n">j</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">][</span><span class="pl-n">j</span><span class="pl-p">]);</span><span class="pl-c1">//读入</span>
    <span class="pl-p">}</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">hh</span><span class="pl-o">=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">hh</span><span class="pl-o">&gt;=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">hh</span><span class="pl-o">--</span><span class="pl-p">)</span>
    <span class="pl-p">{</span>
        <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">hh</span><span class="pl-p">][</span><span class="pl-mi">0</span><span class="pl-p">];</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">find</span><span class="pl-p">(</span><span class="pl-n">hh</span><span class="pl-p">)</span><span class="pl-o">!=</span><span class="pl-n">find</span><span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">hh</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">])</span><span class="pl-o">&amp;&amp;</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">hh</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">&gt;=</span><span class="pl-n">hh</span><span class="pl-p">)</span><span class="pl-c1">//判断之前是否已经连接过，或是后面会连接</span>
        <span class="pl-p">{</span><span class="pl-c1">//连接这两个点</span>
            <span class="pl-kt">int</span> <span class="pl-n">xx</span><span class="pl-o">=</span><span class="pl-n">find</span><span class="pl-p">(</span><span class="pl-n">hh</span><span class="pl-p">),</span><span class="pl-n">yy</span><span class="pl-o">=</span><span class="pl-n">find</span><span class="pl-p">(</span><span class="pl-n">a</span><span class="pl-p">[</span><span class="pl-n">hh</span><span class="pl-p">][</span><span class="pl-n">i</span><span class="pl-p">]);</span>
            <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">xx</span><span class="pl-o">&lt;</span><span class="pl-n">yy</span><span class="pl-p">)</span>
            <span class="pl-p">{</span>
                <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">xx</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">yy</span><span class="pl-p">;</span>
                <span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">yy</span><span class="pl-p">]</span><span class="pl-o">+=</span><span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">xx</span><span class="pl-p">];</span><span class="pl-c1">//危险程度累计</span>
            <span class="pl-p">}</span>
            <span class="pl-k">else</span>
            <span class="pl-p">{</span>
                <span class="pl-n">f</span><span class="pl-p">[</span><span class="pl-n">yy</span><span class="pl-p">]</span><span class="pl-o">=</span><span class="pl-n">xx</span><span class="pl-p">;</span>
                <span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">xx</span><span class="pl-p">]</span><span class="pl-o">+=</span><span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">yy</span><span class="pl-p">];</span><span class="pl-c1">//危险程度累计</span>
            <span class="pl-p">}</span>
        <span class="pl-p">}</span>
        <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">pd</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span><span class="pl-o">&gt;</span><span class="pl-n">n</span><span class="pl-o">/</span><span class="pl-mi">2</span><span class="pl-p">)</span><span class="pl-c1">//判断危险程度是否超过n/2</span>
        <span class="pl-p">{</span>
            <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-n">hh</span><span class="pl-p">);</span><span class="pl-c1">//输出</span>
            <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span><span class="pl-c1">//直接退出</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
    <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
</cpde></pre></div>